In a survey of 305 registered voters, 130 of them wished to see Mayor Waffleskate lose her next election. Construct a 95% confidence interval for the proportion of registered
Voter who want to see Mayor Waffleskate defeated.
A) $0.371

Question

In a survey of 305 registered voters, 130 of them wished to see Mayor Waffleskate lose her next election. Construct a 95% confidence interval for the proportion of registered
Voter who want to see Mayor Waffleskate defeated. 
A) $0.371 < p < 0.482$
B) $0.380 < p < 0.473$
C) $0.317 < p < 0.535$
D) $0.398 < p < 0.455$

Quizplus · Accepted Answer

The sample size is 305 and 130 of them wished to see Mayor Waffleskate lose her next election. So the sample proportion is 130/305 = 0.426. The standard error of the proportion is sqrt(0.426 * 0.574 / 305) = 0.031. The 95% confidence interval is 0.426 +/- 1.96 * 0.031 = (0.371, 0.482).

In a Survey of 305 Registered Voters, 130 of Them 0.371<p<0.4820.371 < p < 0.4820.371<p<0.482

In a Survey of 305 Registered Voters, 130 of Them $0.371 < p < 0.482$